Let-off means for textile machines and the like



Nov. 24, 1959 G. E. cLENTlMAcK 2,9T4092 LET-OEE MEANS EoR TEXTILE MACHINES AND TEE LIKE Filed sept. 2e, 1957 a sheets-sheet 1 FIG. I

CLENTI MACK A TTORNE Y Nov. 24, 1959 LET-OFF MEANS FOR TEXTILE MACHINES AND THE LIKE Filed Sept. 26, 1957 l Milli G. E. cLl-:NTlMAcK 2,914,092

2 Sheets-Sheet 2 INVENTOR. GEORGE E. CLENTIMACK A TTORNE Y United States Patent() 'LET-OFF MEANS FOR TEXTILE MACHINES AND THE LIKE George E. Clentimack, North Attleboro, Mass., assignor to Draper Corporation, Hopedale, Mass., a corporation of Maine Application September 26, 1957, Serial No. 686,419

8 Claims. (Cl. 139-108) This invention pertains to, means for letting olf warp or other threads from beams or the like in textile or other similar machines, and particularly to control of the letoif means and function so as to deliver the warp threads uniformly under a prescribed condition.

It is a general object of the invention to devise a means including a positively driven variable speed system for continuously advancing the beam from which material is to be let off, which will so control that function from a point of starting from a full beam of considerable diameter to empty beam condition, and of maintaining a substantially constant tension condition inthe material thus fed or advanced.

A more specific object is that of providing an articulated or interlinked control means for governing the output speed of the let-olf unit which shall be primarily under the inuence of a control from the beam itself and responsive to changes in eiiective diameter thereof and secondly, but simultaneously, a control responsive to the tension value in the warp sheet or other material being let olf.

It is a further object to devise means functioning as above indicated which shall maintain a linear condition, both from the beam follower and from the tension respon* sive side, so that, even for beams of the very largest diameters practical, the mechanism may be depended upon to deliver material under the closest control and without need for adjustments of any nature, either manual or automatic.

Other objects will appear from the following detailed disclosure.

ln looms, knitting machines, and other textile and comparable machinery, Warp or similar threads wound in parallelism on a beam or beams are fed or let off at a rate dependent upon that at which they are required to be advanced for purposes of forming a fabric or the like. Usually these beams are advanced by a let-off or drive means the speed of which must be varied to compensate for decrease in diameter of the supply on the beam and also for maintaining a uniform tension condition in the material.

Various devices have been employed for this purpose, for example, those of applicants U.S. Patent 2,720,094 and 2,792,023. ln` these which are shown as applied to looms and to knitting machines, but which are also applicable to other mechanism in which a beam is rotated to advance strand or other material, the control is taken entirely from a tension sensing means applied to the warp sheet or the like as it is drawn from the beam. These devices function very well indeed and avoid the utilization of any beam follower, but for use in situations. where control from a very large to a small diameter is required, or Where the speed ratio `varies greatly, applicant has discovered that the system involving a combination of parts functioning as hereinafter set forth serves very effectively with little chance for error and no requirement for unduly fine settings.

Control of the variable speed unit is primarily derived from a beamA follower whichv functions. to change speed linearly rather than in a` non-linear fashion as would be the case if it were to function directly in response to the effective beam diameter. Thus at one. sideV of an interlinked or articulated control means which may preferably comprise levers, one of which is hinged to the rst, a` denite positional relationship is established: in accordancev j with the instantaneous, effective beam diameter.

At the other part of this articulated lever system which may be thought of as a secondary control or as a final, sensitive, tension balancing means, the value of tension in the material let off is transmitted through to the variable speed device so that changesv in` tension may be quickly compensated to the end that the. tension values may be,

confined within permissible tolerances.

The invention will be described in greater detail by reference to a preferred embodiment thereof as illustrated in the accompanying figures of drawing, wherein:v

' ried one end of a warp beamflZ on which are wound the threads constituting a warp supply 13; The. beam, of course, has a core at each., end of which` is provided an end ange llt, one of Whiclicarries a gear 15v with which meshes a pinion 16. The latter is xed to one end of a,

shaft 17 borne in a bearing member 18 xed in the loomside, while at the opposite end this shaft has keyed to it in a driving relationship a worm gear 19.

The drive to this worm gear is taken in the rst instance, from some` constantly rotating shaft in the loom, for eX- ample, from the camshaft. That drive may be by chain 26 to a sprocket 21 on an input shaft, 22. This shaft is carried in suitable bearings in a casing 23, the latter, in turn, being attached to a4 separate casing 24 for a worm 25 and worm wheel 26. The worm 25 is fast to output shaft 27 borne in and extending throughy both casings. Worm wheel 26 is fast to the upper end of a shaft 28 eX- tending downwardly to drive the worm wheel 19 through a worm 29.

Now having alluded to so much of the variable speedl drive, the input4 shaft drive is carried through to the out.- put shaft through a plurality of disks. These are keyed to each shaft, but permitted to slide along the shaft. Disks.

3G* on shaft 22 mesh with one or more intermediate disks 3l on a movable shaft or center 32, and these, in turn, mesh with and rotate disks. 33 on shaft27. A carriage or cradle 34 is swingably mounted to carry the sha/ft 32 and may be movedby a single link or rod 35-to mesh the disks 31 more deeply with those at the inputV side and less deeply at the output side, or vice versa.

Reference is'again made to the patents previously cited for a` complete description of the details of this unit. While the control in the devices of the patents functions through a continuously oscillated actuator, that is notv needed here and movements of the movabler or intermediate disk or disks are effected by mechanism to be The lever 39 is formed as shown in Figs. 3, 4 and 5 with a hub 41 intermediate its ends but much closer to pivot 40 than to the free end of the lever. The end of rod 35 is threaded into a hub 42, a part of a hand wheel 43, the hub 42 being grooved as at 44. This hand wheel and hub are secured to the rod by means of a lock nut or some other locking means and by turning the hand wheel the rod threaded into a part of the yoke 34 or an extending arm thereof, the central position or other adjustment f the variable transmission may be set. This rod and its effect are very similar to those of the rod 108, Patent No. 2,720,094 and of rod 112, Patent No. 2,792,023, except that here the rod is moved axially, whereas in the patents it is rotated and moves a nut threaded to it.

Hub 42 may be turned, but is restrained axially by dog headed set screws 45 and 46 locked in position by nuts 47 and 48. This connection permits a swinging of the levers without disturbing alignment of the rod. There is a small amount of play between hub 42 and the bore of hub 41, but not enough to permit the set screws to bear very much off center in groove 44.

Primary control from the instantaneous beam diameter is derived through a beam follower or roller 49, pivoted at the end of an arm 50, Figs. l and 2. Arm 50 is fixed. to a shaft 51 pivoted at a bearing 52 in the loomside andv having another arm 53 as its other end. A spring 54 anchored at one end to the bearing and at the other to a collar 55 presses the follower against the material on the beam.

The swinging movement of this arm 50 is transmitted to the end of lever 39 through a two armed lever 56 pivoted at 57 and connected by a link 58 to a pivot 59 at the lever 39. At the lower end lever 56 is provided with a follower 60 which functions in a beam follower cam slot 61.

A beam follower of this type if allowed to affect the variable speed unit directly would not produce therein speed changes following a straight line or linear response. That is desirable here and the contour of cam 61 is accordingly laid out to produce such response.

Actually, the majority, perhaps 90%, of the control for the variable speed unit is derived from the follower at the beam, but while in theory that might be considered to be sufficient, in practice the tension in warp threads or other material .would not follow precisely and the lever 36 is controlled by the tension in that material so that a secondary or sort of micrometric control is provided.

The usual whip roll or tension bar is effective through a depending arm 62 or the like, to move a rod 63 axially and to affect the lever 36 through a fiexible connector 64 fixed in a clamping col-lar 65 adjustable along the rod 63 and to an arm 66. The latter connects to and is in effect an extension of an angularly shaped arm, a part of the lever itself. y

Since the lever is anchored at 37, movements of the rod 63 as tension varies in the warp material affect arm 66 to swing lever 36 slightly about that fixed pivot and the interlinked or articulated end 40 of lever 39 will be moved. As pivot 59 will be momentarily stationary, rod 35' will be moved appropriately to adjust the disks 31 as needed to change the output to the beam and to speed it up or slow it down thereby to keep the tension at some value within the range to be tolerated.

The relatively flexible strip 64 serves to take the twist as the parts are moved and also, to absorb periodic but brief tension variations while it will transmit motion of the rod 63 incidental to appreciable tension disturbances which would tend to be permanent if not corrected.

Of course, both controls function together, and since they are both effective on a single controller rod 35, the action is direct, the device simple, and the articulated levers, one end of one of which is anchored as set forth comprise a very precise means to position parts for correct action at all times.

Upon starting a new beam, the arm 50 sets the parts to proper basic position through the cam 61, link 58, etc., and there is no requirement for complex initial adjustments or for running a long length of imperfect cloth before the parts come to proper speed. It then continues to induce the gradual change necessary as the material on the beam vis fed and its diameter, of course, reduced. The range built in is sufiicient to take care of the largest beam diameter desired to be used down to a reasonably sized core for such a beam.

The secondary control is continuously effective to maintain and/or reestablish the proper output speed for maintaining correct tension.

The variable speed device herein described by Way of example may, of course, be modified within limits as long as it provides the proper range, drives positively enough and is capable of being controlled by the unit herein set forth and claimed.

While a loom has been used as an example of a specific installation in which the invention may well serve, other similar machines in which material wound on a beam is to be advanced at a uniform rate are to be understood as being included in those uses in which the invention is advantageously employed.

I claim:

1. In a textile machine of the type described in which warp threads wound on a beam are drawn from that beam to be incorporated into a fabric, the combination of a let-off for said beam which comprises a constantly driven variable speed driving means which includes an input shaft driven at a constant speed, an output shaft, and rotary drive means for transmitting torque from the input to the output shafts which means is variably positionable to increase or decrease the speed of the output shaft relative to the input, and a control for the output of said means which comprises a single movable member and, effective thereon, an articulated lever system one of which is positioned in accordance with the effective diameter of material on said beam and the other of which transmits to said single movable member, indications of tension in said material as drawn from the beam.

2. In a textile machine of the type described in which warp threads wound on a beam are drawn from that beam to be incorporated into a fabric, the combination of a letoff for said beam which comprises a constantly driven variable speed driving means which includes an input shaft driven at a constant speed, an output shaft, and rotary drive means for transmitting torque from the input to the output shafts which means is variably positionable to increase or decrease the speed of the output shaft relative to the input, and a control for the output of said means which comprises a single movable member and, effective thereon, articulated levers, an anchor point about which one of said levers may swing, means for varying the position of said levers including connections one of which is governed in accordance With the amount of material on said beam and another of which transmits through those levers indications of tension conditions in material as drawn from the beam.

3. In a textile machine of the type described in .which warp threads wound on a beam are drawn from that beam to be incorporated into a fabric, the combination of a let-off for said beam which comprises a constantly driven variable speed driving means and a control for the output of said means which comprises a control member, and, effective thereon, levers including a short lever, an anchor pivot for one end of said short lever, a second lever of substantially greater length than that first mentioned, means by which said levers are articulated for action either singly or jointly, means interconnecting said control member for actuation by said lever of greater length and means by which said short lever is moved in response to change of tension values in the material advanced from said beam and by which said lever of greater length is caused to change position as the diameter of material on said beam decreases in diameter.

All

4. In a textile machine of the type described in which warp threads wound on a beam are drawn from that beam to beincorporated into a fabric, the combination of a let-off for said beam which comprises a constantly driven variable speed driving means which includes an input shaft driven at a constant speed, an output shaft, and rotary drive means for transmitting torque from the input to the output shafts which means is variably positionable to increase or decrease the speed of the output shaft relative to the input, and a control for the output of said means which comprises a single movable member and, effective thereon, articulated levers, an anchor point about which one of said levers may swing, means for varying the position of said levers including connections one of which is governed in accordance with the amount of material on said beam and another of which transmits through those levers changes in tension values in the .material drawn from the beam which tend to be permanent.

5. Mechanism as' defined in claim 1 wherein that means which is effective upon said articulated lever system to position it in response to changes in effective diameter of the material of said beam is so devised as to affect speed changes linearly.

6. Mehcanism as defined in claim 1 wherein that means which is effective upon said articulated lever system to position it in response to changes in effective diameter of the material of said beam comprises a pivoted arm, a follower carried by said arm and positioned to bear upon the material on said beam, a cam and follower means and linkage therefrom to said lever system, said cam having such contour as to effect speed changes linearly.

7. In a textile machine of the type describedrin which warp threads wound on a beam are drawn from that beam to be incorporated into a fabric, the combination of a let-olf for said beam which comprises a constantly driven variable speed driving means which includes an input shaft driven at a constant speed, an output shaft, and rotary drive means for transmitting torque from the input to the output shafts which means is variably positionable to increase or decrease the speed of the output shaft relative ot the input, and a control for the output of said means which comprises a single, speed changing member and, effective thereon, an articulated lever system one of which is positioned by a beam follower and linkage from said follower having cam and follower means, said cam being so contoured as to alter a nonlinear response to one substantially linear, and the other of which transmits to the other lever in said system indications of tension in the material being advanced from said beam.

8. In a textile machine of the type described in which warp threads wound on a beam are drawn from that beam to be incorporated into a fabric, the combination of a letoff for said beam which comprises a constantly driven variable speed driving means which includes an input shaft driven at a constant speed, an output shaft, and rotary drive means for transmitting torque from the input to the output shafts which means is variably positionable to increase or decrease the speed of the output shaft relative to the input, and a control for the output of said means which comprises a single, speed changing member and, effective thereon, an articulated lever system one of which is positioned by a beam follower and linkage from said follower having cam and follower means, said cam being so contoured as to alter a non-linear response to one substantially linear, and the other of which comprises linkage having interposed therein a resilient, vibration absorbing member for transmitting to the other lever in said system indications of tension in the material being advanced from said beam.

Beall Sept. 2, 1952 2,755,822 Hunt July 24, 1956 2,812,780 Sakamoto Nov. 12. 1957 

